TLUX
A retail POS and batch-inventory system — multi-invoice checkout, FEFO stock allocation by expiry date, and barcode scanning from a phone camera.
An internal operations platform for retail stores, built on the Next.js App Router with Express and MongoDB. Stock is never stored on the product — it is the sum of what remains across intake batches — so every checkout draws down stock FEFO, earliest expiry first, inside a transaction that records exactly which batches were consumed. Cashiers keep several invoices open at once; each one is a draft order held server-side, so parked carts survive a page reload. Barcodes come from a USB reader or from a phone camera paired over QR and socket.io, and the code's prefix tells the register whether it is a product, a per-line discount label, a promo code or a member card. It also ships a customer-facing second screen that mirrors the cart and the PayOS transfer QR in realtime, accent-insensitive Vietnamese fuzzy search via Elasticsearch, four-role access control, a loyalty-points ledger, and 80mm thermal receipts.